Consumable hot top with inserts of exothermic material



Oct. 19, 1965- M. D. LA BATE 3,212,749

CONSUMABLE HOT TOP WITH INSERTS OF EXOTHERMIC MATERIAL Filed March 24,1964 &

IN V EN TOR.

Micheal Dona/d LaBale ATTO ENE).

United States Patent 3,212,749 CONSUMABLE HOT T01 WITH INSERTS 0FEXOTHERMIC MATERIAL Micheal Donald La Bate, Kay St., Wampum, Pa. FiledMar. 24, 1964, Ser. No. 355,998 9 Claims. (Cl. 249200) This applicationis a continuation-in-part of my copending application Serial No.114,162, filed June 1, 1961, now abandoned.

This invention relates to a hot top and more particularly to a totallyconsumable hot top for application to an ingot mold in which ingots ofmetal are formed.

The principal object of the invention is the provision of a consumablehot top incorporating inserts of exothermic material for maintainingmolten metal poured in the mold and hot top in a molten state toeliminate piping and cracks forming the ingot.

A further object of the invention is the provision of a hot top withinserts of exothermic material capable of creating temperatures inexcess of 3100 F.

A still further object of the invention is the provision of a hot topincorporating sections of exothermic material positioned therein so asto create areas of higher temperature than that of the molten metal inthe hot top in desirable locations within the hot top to maintain themetal therein in a molten state and permit cooling and setting thereofprogressively from the lower portion of the hot top upwardly therein.

Consumable hot tops have been heretofore proposed in the art and thyehave been generally ineffective in use in that they would not alwayshold the molten metal adequately and more particularly in that their usewas limited to molten metal within certain restrictive temperatureranges. Such hot tops as well as those formed of nonconsumable materialas known in the art did not provide any means of preventing the coolingof the metal in the hot top by adding to the temperature thereof. On thecontrary, while they slowed down the cooling ratio as compared with thebody area of the ingot it was frequently in such limited relativetemperature range as to preclude the maintenance of molten metal withinthe hot top area as necessary to fill piping and cracks forming in thesolidifying ingot. Consumable hot tops to be completely effective musttherefore be capable of withstanding temperatures of various moltenmetals and retaining their position on the ingot mold despite tendenciesto float on the metal poured therein and more importantly they mustdelay the cooling action of the metal whereby piping and cracksotherwise formed in the ingot mold are eliminated and at the same timethey must be formed of a material that will become totally consumedand/or disintegrate shortly after the ingot has set. These problemspresent a complex situation as the means for meeting some of theproblems seem to be contrary to the means for accomplishing the others.

The present invention provides a consumable hot top that meets all ofthese problems successfully.

With the foregoing and other objects in view which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts and in the details of construction hereinafterdescribed and claimed, it being the intention to cover all changes andmodifications of the example of the invention herein chosen for purposesof the disclosure, which do not constitute departures from the spiritand scope of the invention.

FIGURE 1 is a perspective view of a consumable hot top formed inaccordance with the invention.

FIGURE 2 is a plan view of one portion of the hot top shown in FIGURE 1.

3,212,749 Patented Oct. 19, 1965 FIGURE 3 is a plan view of anotherportion of the hot top shown in FIGURE 1.

FIGURE 4 is a vertical section through FIGURE 2.

FIGURE 5 is a vertical section through FIGURE 3.

FIGURE 6 is a vertical section through a portion of an ingot moldshowing the hot top positioned thereon and an ingot poured therein.

By referring to the drawing and FIGURE 1 in particular, it will be seenthat a consumable hot top has been disclosed which comprises a pair ofoppositely disposed elongated side sections 10 and 11 and a pair ofoppositely disposed end portions 12 and 13. The side portions 10 and 11and the end portions 12 and 13 are duplicates and they are all formed ofmaterial which will be totally consumed and/ or disintegrate shortlyafter the solidifying of an ingot poured therein. The side portions 10and 11 have end extensions 14 and 15 formed therein midway between theirupper edges 16 and their lower edges 17 and the end portions 12 and 13have oppositely disposed pairs of extensions 18 and 19 thereon adjacenttheir uppermost and lowermost edges 20 and 21 respectively. The sideportions 111 and 11 have rectangular metal clips 22 partially embeddedin their lower edges 17 and the end portions 12 and 13 have rectangularmetal clips 23 partially embedded in their lower edges 21. Alternately,notches may be formed in the lower edges 17 and 21 and the metal clips22 and 23 positioned within the area of the notches.

The side portions 10 and 11 and the portions 12 and 13 of the consumablehot top are formed of material which include ingredients that will burnsuch as sawdust, Wood chips, rice hulls, wheat kernels or the like andingredients that will disintegrate to a fine powder or granular form,such as sand, granulated slag, powdered dolomite or powdered fired clay.Suitable ingredients from either of these groups are combined in thepresence of a binder which may comprise sodium silicate or a resin basebinder such as urea-formldehyde. An example of a desirable material mixcomprises a batch including 40 lbs. of sawdust, 140 lbs. of raw dolomiteand lbs. of sodium silicate. It is apparent that the foregoing mixtureconsists essentially of about 15% by weight of sawdust, about 54% byweight of dolomite, and about 31% by weight of sodium silicate. Thismixture may be altered by substituting an equivalent quantity of woodchips, rice hulls, or wheat kernels for the sawdust or it may be variedby substituting an equivalent quantity of sand, or granulated slag, orground fired clay for the dolomite. Such combinations may be heldtogether by 50 lbs. of the resin urea formaldehyde rather than the 80lbs. of sodium silicate. It is apparent that the last-mentioned mixturemay consist essentially of about 17% by weight of sawdust, about 61% byweight of dolomite and about 22% by weight of resin urea-formaldehyde.These mixtures tend to dry and set and form a reasonably durablestructure capable when assembled into a hot top or directly formed in ahot top shape of holding molten metal during its cooling and settingperiod and thereafter being consumed and/or disintegrated.

Those skilled in the art will observe that hot tops formed of thematerials such as disclosed will not contribute to the temperature ofthe molten metal by their consumption but will merely act as efiicienthot tops in the usual manner and conveniently dispose of themselves whentheir utility has ceased. It will occur to those skilled in the art thatit is desirable to maintain the molten metal in the hot tops in a moltenstate over a sufiicient period of time to permit the cooling and settingof the metal in the mold therebeneath thereby avoiding the formation ofcracks and piping and other flaws in the cast ingot.

In order to accomplish this, the consumable hot top disclosed herein hassections 24 and 25 of exothermic material positioned therein inlocations where it will most effectively contribute to the maintenanceof temperatures capable of maintaining the metal in the hot top in amolten state.

An example of the exothermic material may comprise:

FeO 9.50% Al 23.48% F6 35.39% A1 0 14.46% SiO 2.48% C'uO 1.20% MnO .37%NaCl 4.75% CaO 1.40% Ign. Loss 5.02% MgO 2.06%

By referring to the drawings and FIGURES 2 and 3 in particular, it willbe seen that broken line outlines of the exothermic sections 24 and 25will be seen and that the section 24 of exothermic material ispositioned adjacent the lower edge 17 of the side portions and 11 whilethe sections 25 exothermicmaterial are positioned relatively closer tothe central area of the end portions 12 and 13 of the hot top. In orderthat the hot tops shown in FIGURE 1 may be formed and held in assembledrelation the side sections 10 and 11 and end sections 12 and 13 aremolded or otherwise formed of the material hereinbefore specified withthe clips 22, 23 positioned therein along with the sections 24 and 25 ofexothermic material. The formed sections are then assembled inoppositely disposed pairs as seen in FIGURE 1 and it will be observedthat the sections are provided with longitudinally extending grooves 26and 27 respectively in their outer sides and which grooves 26 and 27 arearranged to register in end to end engagement so that bands of steelstrapping 28, 28 may be positioned about the four sides of the hot topsand secured to one another as by clips 29, 29. It will be seen that theend extensions 14 and 15 overlie the adjacent ends of the end sections12 and 13 and that the end extensions 18 and 19 overlie the adjacentends of the side sections 10 and 11 and are positioned above and belowthe extensions 14 and 15.

The consumable hot top is thus securely assembled and when positioned inan ingot mold M as seen in FIGURE 6, it will become attached theretowhen the molten metal flows through the clips 22 and 23, and it willhold the molten metal while the inner surfaces of the hot top burn awayand expose the sections 24 and 25 of exothermic material which will thenignite and add temperature to the molten metal to maintain the same in amolten state for a desirable interval. The hot top is so formed and thematerials thereof so chosen that its rate of consumption is controlledso that it will retain the metal while it is in molten state and thatimmediately after the metal has solidified following the successfulformation of a perfect ingot the remaining portions of the hot top willbe consumed and/or disintegrated including the steel strapping. Metalhandles as seen in FIGURES 1, 2 and 4 may be used if desired tofacilitate handling the hot top.

It will thus be seen that a hot top meeting the several objects of theinvention has been disclosed, and having thus described my invention,what I claim is:

1. A consumable hot top comprising a walled structure having open upperand lower ends wherein said walled structure is formed of solid shapedsections of consum- 4 able and disintegratable material, said materialconsisting essentially of about 15% by weight of sawdust, about 54% byweight of dolomite and about 31% by weight of sodium silicate, andinserts of exothermic material disposed within said solid shapedsections.

2. A hot top as defined in claim 1 wherein the inserts of exothermicmaterial are located in the lower half of each of said solid shapedsections.

3. A hot top as defined in claim 1 wherein the inserts of exothermicmaterial comprise:

FeO 9.50% Al 23.48% Fe O 35.39% A1 0 14.46% SiO 2.48% CuO 1.20% MnO .37%NaCl 4.75% CaO 1.40% Ign. Loss 5.02% MgO 2.06%

4. A consumable hot top comprising a walled structure having open upperand lower ends wherein said walled structure is formed of solid shapedsections of consumable and disintegratable material, said materialconsisting essentially of about 17% by weight of sawdust, about 61% byweight of raw dolomite, and about 22% by weight of resinurea-formaldehyde, and inserts of exothermic material disposed withinsaid solid shaped sections.

5. A hot top as defined in claim 4 wherein the inserts of exothermicmaterial are located in the lower half of each of said solid shapedsections.

6. A hot top as defined in claim 4 wherein the inserts of exothermicmaterial comprise:

FeO 9.50% Al 23.48%

F6203 A1203 S10 2.48% C 1.20% MnO 37% NaCl 4.75% CaO 1.40% Ign. Loss5.02% MgO 2.06%

7. A consumable hot top mixture consisting essentially of about 15 byweight of sawdust, about 54% by weight of dolomite and about 31% byweight of sodium silicate.

8. A consumable hot top mixture consisting essentially of about 15 byweight of sawdust, about 54% by weight of raw dolomite, and up to about31% by weight of sodium silicate.

9. A consumable hot top mixture consisting essentially of about 17% byweight of sawdust, about 61% by weight of dolomite, and about 22% byweight of resin ureaformaldehyde.

References Cited by the Examiner UNITED STATES PATENTS 1,819,364 8/31Firth 22147 2,841,843 7/58 Nouveau 22147 3,103,045 8/63 La Bate 22147FOREIGN PATENTS 799,798 8/58 Great Britain.

J. SPENCER OVERHOLSER, Primary. Examiner.

MARCUS U. LYONS, Examiner.

7. A CONSUMABLE HOT TOP MIXTURE CONSISTING ESSENTIALLY OF ABOUT 15% BY WEIGHT OF SAWDUST, ABOUT 54% BY WEIGHT OF DOLONITE AND ABOUT 31% BY WEIGHT OF SODIUM SILICATE. 